Properties of hemp fibre polymer composites -An optimisation of ...

ABSTRACT
Characterization of hemp fibers was carried out to investigate the mild defibration with
Phlebia radiata Cel 26, a fungus which selectively degraded the epidermis and the
lignified middle lamellae. Thin fiber bundles could thereby be produced. The single fiber
S2 layer consisted of 1-5 μm thick concentric layers constructed of ca. 100 nm thick
lamellae. The microfibril angle showed values of 0-10° for the main part of S2 and 70-
90° for S1. The low S2 microfibril angle resulted in fiber bundles with high tensile
strength (960 MPa) decreasing to 850 MPa after defibration due to degradation of non
cellulosic components.
Key words: Cannabis sativa L., bast fibers, cell wall structure, microfibril angle,
electron microscopy, histochemistry, Phlebia radiata Cel 26.
ACKNOWLEDGEMENTS
This work forms part of the project "High performance hemp fibers and improved fiber
network for composites" supported by the Danish Research Agency of the Ministry of
Science, the EU COST action E20 and the Wood Ultrastructure Research Center
(WURC), Sweden. The support to Ph. D. student Anders Thygesen from WURC is
gratefully acknowledged. Senior scientist Poul Flengmark (Danish Institute of
Agricultural Sciences) is acknowledged for growing the hemp, Mrs. Ann-Sofie Hansen
(WURC) for setting up the fungal cultivations, M. Sc. Frants T. Madsen (The Royal
Veterinary and Agricultural University) for instruction in fiber bundle testing and Mr.
Henning K. Frederiksen (Risø National Laboratory) for help in composite fabrication.
Dr. Claus Felby (The Royal Veterinary and Agricultural University) is acknowledged as
supervisor for Anders Thygesen.
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